1. Field of the Invention
This invention relates to a medical apparatus and method for occluding the flow of blood at a preselected position within a vessel of the human body, and more particularly, relates to an aneurysm embolization device for filling a high volume or wide neck aneurysm and a deployment system for releasing the embolization device within the aneurysm.
2. Description of the Prior Art
For many years physicians have been placing various devices within a blood vessel of the human body in order to treat an aneurysm by promoting thrombus formation. Such devices include balloons, coils, fiber retainers, multi-element anchors, and micropellets. Balloons are introduced into an aneurysm using a deployment catheter and then inflated within the aneurysm. The balloon prevents the flow of blood within the parent vessel from entering the aneurysm.
Another type of occluding device is an embolic coil. Embolic coils may take the form of helically wound coils, randomly wound coils, coils wound within other coils, or many other coil configurations. These coils are generally formed of metallic materials, such as platinum, gold, and tungsten, or alloys of these metals. Often times, several coils need to be placed within an aneurysm in order to occlude the flow of blood.
Furthermore, a retainer which holds at least one fiber bundle can occlude the flow of blood. The retainer can take the form of a cube, sphere, cylinder, coil, oval, or other similar shape. The thrombogenic fibers are longer than the retainer and can be made of silk, cotton, nylon, or polyurethane. These fiber bundles occlude the flow of blood in a vessel. This device is primarily used in small vessels of the vasculature.
Also, a multi-element occlusion device can stop the flow of blood in a vessel. This device has two or more elements connected by at least one metallic or nonmetallic fiber. The elements can be particles or coils with various sizes and shapes. The device is deployed with a catheter and flows downstream until the anchoring element lodges against the vessel wall. The multiple elements connected to the anchor help create deep occlusion. This device cuts off the flow of blood in a vessel and reduces the risk of continued canalization within the vessel.
Finally, micropellets are cylindrical members formed from a biocompatible foam or gel material. Several micropellets can be linked together with a carrier wire and when the micropellets are soaked in a fluid, they expand to fill an aneurysm. The swelled micropellets occlude the flow of blood and become fixed within the aneurysm.
Balloons, coils, fiber retainers, multi-element anchors, and micropellets are devices beneficial in treating aneurysms. However, the present invention is useful in treating large aneurysms or wide neck aneurysms. The present invention is an embolization device which occludes the flow of blood in an aneurysm, reduces the risk of becoming dislodged, allows blood to continue flowing through the parent vessel, and allows for retrieval or realignment.